The present invention concerns a self-pumping solar heating system for homes or commercial buildings relying on a gravity imbalance due to the geyser discharge of collector liquid into a header to pump the heated liquid to an end use such as a heat exchanger below the collector.
In general, solar heating systems utilize one of two systems for heat transfer, thermosiphon or pumped loop. The major drawback to the thermosiphon system is the physical disposition of components requiring overhead storage of the heated liquid. In the pumped loop system, the storage receptacle may be below the collector panel but the system incurs an external energy cost and the utilization of costly components such as pumps, controllers, valves, sensors, which eventually require maintenance or replacement.
Attempts to overcome the shortcomings of both systems have been made with solar heating systems which utilize a gas bubble flow such as disclosed in U.S. Pat. No. 4,246,890 wherein the bubble flow or stream is remote from a solar collector but serves to lift collector heated liquid. U.S. Pat. No. 4,224,925 discloses a "pumpless" system which relies on the gravity flow of liquid and on vapor entrainment for liquid circulation. U.S. Pat. No. 4,270,522 discloses a system wherein vapor pressure from a solar collector is used to operate a venturi pump to circulate water through a heat exchanger. U.S. Pat. No. 4,305,382 also discloses a system utilizing a venturi pump to circulate condensate through a solar panel. U.S. Pat. No. 4,270,521 discloses a system wherein a geyser action in conjunction with an ambient air pressure differential is used for water circulation. U.S. Pat. No. 4,237,866 is of interest in that it discloses a series of riser tubes in a solar collector from which tubes vapor and liquid are discharged by geyser action to impinge on a conduit passing through a header embodied heat exchanger which serves to circulate liquid only within the collector itself. The following described system in distinction utilizes geyser action to create a gravity imbalance which serves to circulate a single medium through the entire system.